Speed-measuring machine.



3K & T. KALMUS.

11.: FE 00mm MEASURING MAOEENE,

SPEED APPLIOATZGN 1231) 2313.10, 1009.

l-atented Dec. "7?,

- Improvements in. Speed- Measuring Mamethods of measuring the speed ofautomoretreats from the observer, and the time in- DANIEL r. coms'roox,or BROOKLINE, an

inup a is.

SPEED-MEASURING MASHKNE.

Specification of Letters Iaten'lued Dec. '3, 1909.

Application filed February 10, 199?. Serial .Qo. lY'i',l.2-fl

To all whom it may concern: I

lie it known that we, DAN in F. Corr STOCK and Hennmrr T. KAnMUs,citizens of the United States, residing, respectively, at Brookline andBoston, in the counties of Norfolk and Sufi'olk and State of Massachrrsetts, have invented certain new and useful chines; and we do herebydeclare the following, to be a full, clear, and exact description of theinvention, such as will enable others skilled in the art to which itappertains to make and use the same.

The present invention relates to an inprovement in speed measuringmachines.

The object of the invention is to produce a machine by which the speedof a moving object can be determined. For example, the

biles have been determined by pacing niahines provided with speedindicators; by the-taking of time by'two observers at the ends of ameasured stretch, one observer si naling to the other at the beginningof th time interval, as by dropping a handkerchiei or an electricsignal. The determination of automobile speeds by pacing them is notvery satisfactory, especially as the determination of speed is dependentupon the read ing of a speed indicating device by the per son pacing themachine. The determination of the speed. by timing on a measured'stretchrequires two men and the measuring of a stretch over the entire distanceof which the machine must pass in order to secure a determination of thespeed. Sometimes a machine will stop on the measured course, and. thenthe speed cannot be determined.

According to the present invention two pictures are taken or theautomobile as it terval between is measured by a stop watch. The twopictures of the machine show a difference in the represented length of acertain part of the machine, for convenience the represented wheel gagesmay be taken or the represented lengths of the number plate.

In any given part of. the country the wheel gage is standard and affordsone known measurement. In addition to this we have the focal length ofthe cameras. With these known quantities and the represented length ofthe Wheclgage on the two pictures, it is a matter of elementarymensuration to cone puts the distance that the automobile travelsbetween the time of taking the first picture and the time of taking thesecond picture. This distance, when compared with the elapsed timebetween the taking of the two pictures, readily gives the rate of speedof the automobile.

{if course the inve tion is not limited to use in connection with theuse of measuring automobile speeds. it may be used for measuring thespeed of other things.

The invention consists in the speed measuring apparatus hereinafterdescribed and particularly defined in the claims.

in the accompanying drawings illustrating the preferred form of theinvention Figure 3. is a side elevation, Fi 2 a front elevation and 3 aplan oi a speed measurapparatus embodying the invention.

in the drawings there are represented two. earner; s, an upper camera 1and lower camera fastened together, and which, aside from the mattershereinafter pointed out, are constructed operate in the ordinary way. Tothe upper camera is secured a stop watch which is of the usual type ofstop watches except that it is arranged to measure to 20th seconds. itis arranged with its S'L'Qlll projecting above the top of the uppercamera. To the upper camera is piv oted a lever l; which is normallysupported guides on the sides of the cameras extends from the lowerescapoment lever 12 up to the operatin lever l, where it is providedwith a head 1a which projects through a hole in the operating lever Thestem of the stop watch is located under the operating lever 4: and isaoapted to be opc'ated thereby.

in operation. the observer noting the approach of an automobile, forexample, the speed of which he desires to ascertain, allows it tc passhim and thereupon he 1. :sscs With thumb on the operating lever at theplace marked A thereby starting the stop watch and at the same timedepressing the escapement 10 of the upper camera and taking a photographof the object. After the lapse ofa short interval of time he againdepresses the operating lever 4, this time the interval between thetaking of the twopictures. Upon development of the films the representedlength of the wheel gages in the two pictures may be measured. Thensubstituting the known values in the following equation the distancetraveled by the automobile is readily computed. In this equation D isthe distance traveled by the automobile between the taking of the twopic tures, f the focal length of the cameras, G the wheel gage of theautomobile (ordinarily four feet nine inches,) g the represented lengthof the wheel gage measured on the first film, and g isthe representedwheel gage measured on the second film. Thus Of course all measurements.must be expressed in the same units. Having aseer-- tained the distancetraveled by the automobile between the taking of the pictures andknowing the time interval, the speed is readily determined.

The specific embodiment of the invention, or the specificuse to which itis to be put, is a matter of no moment, as the invention may readily beembodied in other forms without departure therefrom or the exercise ofmore skill than that of a person familiar with the construction of suchapparatus.

Having thus described the invention what is claimed is 2- 1. A speedmeasuring apparatus, having, in combination, two picture makingapparatuses, a stop watch, and connections be- .vision for releasing theescapement of one camera on the starting of the stop watch and forreleasing the escapement of the other camera on the stopping of the stopwatch, substantially as described.

3. A speed measuring apparatus, having, in combination, two picturemaking devices, a time interval measuring device, and connectionsbetween the devices operatingto cause one of the picture making devicesto take a picture at the beginning of the measured time interval and tocause the other picture making device to take a'picture at the end ofthe measured time interval, substantially as described.

4:- A speed measuring device, having, in combination, means for takingtwo pictures and for determining the time interval be tween,substantially as described.

In testimony whereof we our signatures, in presence of two witnesses.DANIEL F. COMSTOCK. HERBERT T. KALM U S. Witnessesr I'IORACE VAN EVEREN,ALICE AcKRoYo.

